Trolley wire tap



July 5, 1949. J, CONRAD 2,475,352

Fig./.

N' 3 H I 37 3a 4 7 3 35 36 33 27 32 34 Fig 3 TROLLEY WIRE TAP Filed April 19, 1948 1 Inventor John F. Conrad W mit,

Patented July 5, 1949 UNITED STATES PATENT OFFICE TROLLEY WIRE TAP John F. Conrad, Ebensburg, Pa.

Application April 19, 1948, Serial No. 21,953

2 Claims. 1

My invention relates to trolley wire taps for connecting mobile electric machines to trolley wires and is designed as an improvement over the tap forming the subject matter of my co-pending application, Serial No. 697,940,, filed September 19, 1946.

By way of premise, the tap of my co-pending application, supra, is of the fused type with a; tubular handle forming fuse casing, a trolley wire engaging hook and a hand guard at one end of the casing, a terminal connection between said hook and fuse including a'shunted spring connector, a conductor cable at the other end of the casing, and a terminal connection between said cable and fuse.

Among the important objects of my instant invention is to provide in such taps a better hook connection capable of withstanding greater tensile strain, a safer, more secure, and longer lasting mounting for the hand guard, an improved shunted spring connector obviating loss of the same when changing fuses and providing for a better electrical connection between the fuse and hook, and a connection between the conductor cable and fuse adapted to hold against unusually heavy and sudden strain and easily and quickly assembled to assure good electrical connection between the cable and fuse.

Other and subordinate objects, within the purview of my invention, together with the precise nature of my improvements, will be readily understood when the succeeding description and claims are read with reference to the drawing accompanying and forming part of this specification.

In said drawing:

Figure 1 is a view in longitudinal section illustrating my improved trolley wire tap in a me ferred embodiment thereof;

Figure 2 is a view in perspective of the shunted spring connector drawn to a larger scale;

Figure 3 is a view in longitudinal section through the same taken on the line 3--3 of Figure 2;

Figure 4 is a composite view in perspective of the screw plug, hand guard, bushing, coupling sleeve, washer and pin for the coupling sleeve, all disassembled; I

Figure 5 is a view in perspective of the socket member forming part of the connection between the conductor-cable and fuse;

Figure 6 is a fragmentary view in longitudinal section of a modified embodiment of my invention; i

Figure 7 is-a similar view of another modified embodiment.

Referring now to the drawing by numerals, and first to Figures 1 to 5 illustrating the preferred embodiment of my invention, I designates the tubular, handle forming, casing for the fuse 2, and which, in the present instance, is preferably formed of Micarta, although other similar insulation material may be used. The casing I is provided with a smooth uniform diameter bore 3.

The connection between the trolley wire engaging hook, designated 4, and the fuse 2 comprises a screw plug 5 of brass, having an inner end, cup-like, cylindrical socket 6 longitudinally slit, as at I, to form resilient gripping fingers 8 on said socket, and which is sleeved for a short distance over one end cap 9 of the fuse 2 with said fingers 8 gripping said cap. The screw plug 5 further includes an axial outer end stud I0 on the end of the socket B opposite the fuse fitting end and which is provided with a threaded end II.

The socket 6 is threaded externally, with the exception of the gripping fingers 8, and turned into a relatively shorter, internally threaded, brass bushing I2 forming an insert in one end of the casing flush with the outer edge of said bushing I2 and said end of the casing I, for a particular purpose presently seen.

The bushing I2 is externally knurled, as at I3, slightly oversize, with respect to the bore 3 of the casing I, and is forced into said bore 3 under heavy pressure, with :1 bonding cement, not shown, applied to the same externallywhereby, afterthe cement has set, said bushing I2 is firmly fixed in and bonded with said bore 3 against pulling loose under exceptionally heavy strains. A pair of diametrically opposite studs I4 are provided on the end of the socket 5 opposite the fuse fitting end and at opposite sides of the stud Ill, for a purpose presently seen.

An internally threaded, externally knurled, coupling sleeve l5 tmned onto a threaded shank IS on the trolley wire engaging hook 4 and also turned onto the terminal end II of the stud I0 connects said shank to said stud II] in axial alignment therewith, whereby said hook 4 is detachably connected to the screw plug 5. A radial locking pin I1 in the coupling sleeve I5 locks said sleeve to said stud III. The coupling sleeve I5 is formed with a circumferential base flange I8 for a particular purpose presently apparent.

The hand guard I9 is of the usual disk-like, washer shape, but is formedof a flame-resistant, non-breakable material, impervious-to moisture absorption and inherently agood insulator, for

instance, butadiene synthetic rubber. The hand guard II is fitted tight around the stud l and clamped against the stud equipped end of the socket I and against the bushing l2, also the adiacent end of the casing I, by the coupling sleeve l and a brass washer 2U interposed between said guard and the base flange [8 of said sleeve [5. In this position thereof, said guard 19 is impaled on the studs l4 and securely held shunted against rotary play.

The shunted spring connector comprises a pair of brass washers 2| connected in the axis thereof by a flexible conductor in the form of a short length of copper cable 22. The washers 2| are provided with axial recesses 23 in outer sides thereof in which the strands of the cable 22 are mushroomed and anchored by solder 24. The usual coil spring 25 of brass surrounds the cable 22 and is interposed between the washers 2| to spread the same apart.

The washers 2| fit loosely in the socket 6 with one fitting fiat against the bottom of said socket and the other similarly fitting against the cap 9 of the fuse 2, and the coil spring 25 is slightly compressed sothat the washers exert pressure against the bottom of the socket 6 and the fuse 2, for a reason presently seen, and the cable 22 electrically connects said fuse with the bottom of said socket 8.

A particular feature of my invention is means for frictionally locking the described shunted spring connector in the socket 6 comprising the following. Peripheral grooves 26 are provided in the washers 2i and in which are seated transversely split expanding rings 21 of copper, for frictionally engaging the circumferential wall of the socket 6 to frictionally lock said connector in said socket against falling out during the operation of replacing the fuse 2.

As will be seen, the described shunted spring connector establishes good electrical contact between the fuse 2 and the screw plug 5, which is to say, the socket 6 of said plug, and which is in good electrical connection with the trolley wire engaging hook 4, and the current is shunted from the fuse 2 to the screw plug 5 by way of the cable 22 so that the coil spring 25 is not used as a primary conductor and the life of the same will not be impaired by the action of heat.

Coming now to the terminal connection for the conductor cable designated 28, the sheath 29 of the said cable 28 has one end thereof extended into and fitted in an annular plug 30 of the same material as the casing l, preferably, but which may be of the same material as the hand guard [5, said plug 30 being tightly fitted, with" A cylindrical brass socket member 35 with an.

internally threaded end 36 and a flat bottomed -ing said fuse in the socket end 31.

Abrassrlngllinthesocketendfl surrounds the strands I3 and said strands are mushroomed, or bent. thereover, as at 40. and clamped by the socket member ll against said ring with the ring clamped against the nut I2. The nut 32 and socket member 35 are dimensioned to pass through the bushing l2 for assembling, or disassembling, the tap. Flat wrench holds are provided on the said end 30 of the socket member 35 for turning the same 01! and on the nut 32 with a wrench.

Aswillbe manifest, the coupling sleeve l5 forms a lock-nut for the trolley wire engaging hook 4 whereby said hook is locked to the stud II and hencetothescrewplugl,sothatsaid hook 4, sleeve liandguard llandscrewplugimaybe detached with the shunted spring connector frictionally held in said P1118. all these parts being detachable as a unit by merely turning the screw plug 5 out of the bushing l2 using the hook 4 as a hand grip. Conversely, these parts may be attached as a unit by merely turning the screw plug, that is, the socket I of said plug 5 into said bushing l2. Also, the socket member 35 and the nut 32 may be moved out of the same end of the casing I by pulling the conductor cable 28 through the plug II, and without detaching the bushing [2.

In the modified embodiment of my invention shown in Figure 6, an optional form of plug for the conductor cable end of the fuse casing l is shown as comprising an annular plug section 39 of butadiene synthetic rubber, but otherwise like the plug II and similarly secured in the end of the casing I, said plug further comprising a brass, annular, inner plug section 42, on the inner side of the plug section 39, against which the nut 4|, corresponding to nut 52, seats flat. The plug sections 39. 42 are suitably sized for extension of the conductor cable 45 therethrough and the annular plug section 42 is knurled, as at 46, and oversized as regards the size of the easing I internally to be imbedded in the wall of said casing when pressed into the same. In this embodiment of the invention, the plug section 38 serves as an insulator, augments the plug section 4| against strain caused by heavy pull on the conductor cable 45. and relieves strain on the cable insulating sheath 4 when said cable is pulled laterally. A coating of phenol glue, not shown, may be applied to the plug section 40 for additionally bonding the same to said casing.

In the modified embodiment of my invention shown in Figure '7, another optional form of plug for the terminal connection between the conductor cable 41 and the casing l is shown as comprising a stepped outer plug section 48 of the same material as the plug section 39 and similarly secured in the casing I, with the smaller part on the inside andcapped by an annular, brass, bell shaped plug section 49 peripherally knurled, as at 5|, and oversized, for the same purpose as the plug section 4!, and also notched, as at 5|, to form resilient out-turned, circumferential sections 52 thereon for biting into the wall of the casing I. A coating of phenolic glue, not shown, may be applied to the plug section 49 in assembling to additionally bond the same with said casing I.

As will be seen, the modified embodiment of plugs shown in Figures 8 and 'I are particularly designed to resist heavy pull against the same and sudden jerking by the conductor cable.

The foregoing will, it is believed, suifice to impart a clear understanding of'my invention, without further explanation. Maniiestly, the

5 invention, as described, is susceptible of modification, without departing from the inventive concept, and right is herein reserved to such modifications as fall within the scope of the appended claims.

Having described the invention what is claimed as new is:

1. In a trolley wire tap, a tubular handle forming fuse casing of insulation material, a conductive bushing fixed in one end of said casing and internally threaded, a conductive screw plug having an externally threaded inner end socket turned into said bushing and adapted to fit over one end of a fuse in said casing, said plug having an axial outer end stud on the other end of the socket, a hand guard of insulation fitted over said stud, a conductive trolley wire engaging hook having a shank aligned with said stud, a coupling sleeve threaded onto said stud and shank for coupling the same together in engaging locked relation and clamping said guard against said socket, and a conductor in said socket electrically connecting the same and said fuse and frictionally locked therein.

In a trolley wire tap, a tubular handle forming fuse casing of insulation material, a conductive bushing fixed in one end of said casing and internally threaded, a conductive screw plug having an externally threaded inner end socket turned into said bushing and adapted to fit over one end of a fuse in said casing, said plug having an axial outer end stud on the other end of the socket, a hand guard of insulation material fitted over said stud and seating on said other end of the socket, a conductive trolley wire engaging hook, means for detachably connecting said stud and hook in locked engaging relation and clamping said guard against said seat, and a conductive connector in said socket adapted to connect said end of the fuse with the bottom of the socket, said plug, guard and means being detachable from said casing as a unit by turning said socket out of said bushing by means of said hook and said connector being frictionally locked in said socket for removal with said plug and subsequent removal from the socket.

JOHN F. CONRAD.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 223,969 Watts Jan. 27, 1880 404,813 Widdicombe June 4, 1889 1,190,524 Douglas July 11, 1916 1,469,652 James Oct. 2, 1923 1,654,475 Wyman Dec. 27, 1927 1,746,650 Harrington Feb. 11, 1930 2,015,619 Crabbs Sept. 24, 1935 2,030,016 McIntosh Feb. 4, 1936 2,077,338 Lingal et a1. Apr. 13, 1937 2,288,680 Chandler July 7, 1942 2,419,152 Mosebach Apr. 15, 1947 

